1. Field of the Invention
The invention relates to a measuring method and a measuring device for frequency selective measurement.
2. Discussion of the Background
Audio devices such as mobile telephones and hearing aids often comprise a transmission technology, which is adapted to the signals to be transmitted. Accordingly, it is not always possible to determine the transmission properties with synthetic signals such as sinusoidal sweeps or multi-sinusoidal sound mixes. Speech codecs of mobile telephones distort the spectrum of such test signals as do frequency-dependent compressors in hearing aids. The measurement of the resting noise is often hindered by so-called noise gates, which switch the output of a transmission path to mute if no input signal is connected.
Traditionally, when testing mobile telephones, a transmission frequency response is often determined through a series of generally gap-free or overlapping spectral transformations, of which the spectrum is averaged at the input and output of the transmission path over the duration of the test signal. In the IEEE standard 269™-2002 dated 25 Apr. 2003, a measurement for the differentiation between spectra simultaneously determined and conditioned in a hearing-compatible manner is calculated at the input and output of the transmission path.